<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=>, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 50px;
            height: 50px;
            background-color: blue;
        }
        div{
            width: 30px;
            height: 30px;
            background-color: red;
            color: teal;
        }
        div p{
            width: 50px;
            height: 50px;
            background-color: yellow;
            color: tomato;
        }
        div#one{
            width: 60px;
            height: 60px;
            margin-bottom: 20px;
            /*background-color: rgba(100,100,100,0.5);*/
            background-color: #ccc;
        }
    </style>
</head>
<body>
    <div id="one"></div>
    <!--<div>hello&ndspword</div>-->
    <div>hello
        <p>word</p>
    </div>
    <p>
    春晓
        春眠不觉晓
        处处闻啼鸟
        夜来风雨声
        花落知多少
    </p>
    <pre>
    春晓
        春眠不觉晓
        处处闻啼鸟
        夜来风雨声
        花落知多少</pre>
</body>
</html>